On the SitePoint PHP blog there's a new tutorial posted showing how to fix Magento login issue with cookies and sessions. This issue can cause a redirect loop but can be fixed.
In this article are looking at how Magento cookies can create issues with the login functionality of both the customer-facing front-end and admin back-end, the reason it occurs and how it should be resolved.
This is also known as the looping issue, as the screen redirects itself to the same screen, even though the username and password is correct.
The post starts with some basic definitions of "cookie" and "session" and gets into more detail on how Magento stores sessions and the places it can store them. The tutorial then covers each of the cookies used and three reasons the login issues might be happening:
- Cookie domain does not match server domain
- Multiple subdomains used and Magento’s cookie configuration is incorrect
- Double front-end cookies causing intermittent login issues
For each several solutions are included with any code or SQL changes that need to happen to correct it.